1. Field of the Invention
The present invention relates to handles, and specifically to handles or grips which are attachable to keys to facilitate their use.
2. Description of Prior Developments
Key of the type widely used for operating locks found in the doors of homes, offices, vehicles and other applications are generally planar or laminal in form. Such keys typically include a base, which is often perforated and which provides a surface to gripping and turning the key, and an integrally formed shaft projecting from the base. Integrally formed on the shaft is a series of irregularities, such as teeth, which are configured to correspond to the mating elements of the lock when inserted therein.
The act of gripping and turning the key base requires the pads of several fingers to be placed together in close proximity in a pincer-like or pinching fashion. The planar form of the key and key base is not chosen primarily for ease of use but to enable inexpensive manufacture, coding and compact storage of several keys as on a single key ring.
In general, prior key holders included various key attachments for containing one or more keys and for aiding in identifying and selecting individual keys. These prior attachments take advantage of the compact planar form of the typical key by making the key cases and holders substantially planar as well. See, for example, U.S. Pat. No. 5,487,291.
Prior key cases and holders are typically made laminal as suggested by the flat keys with which they are used. Also transferred from the key to the key holder is the requirement that the key user""s fingers assume a pincer-like position to grip and twist the device holding the key. See, for example, U.S. Pat. Nos. 4,516,000 and 4,910,983. Arthritis and other debilitating medical conditions can impair digital dexterity and cause such a pinching, twisting action to be painful, awkward or even impossible to perform.
Many devices, such as eating utensils and writing instruments, have been specifically designed to minimize discomfort and enable their usage by persons afflicted as mentioned above. However, there yet appears to be a need for a device to allow the easier use of a common key.
The act of pinching a planar object often causes longer fingernails to come into contact with one another, the key, the lock or an adjacent object. This contact can damage or ruin any cosmetic treatment that has been applied to the fingernails or cuticles.
U.S. Pat. No. 3,355,917 to Albert and U.S. Pat. No. 4,583,383 to Bosco et al. create or use a generally L-shaped lever to turn a key. In Albert, the keys are swingably carried on pins attached to a key holder. In an in-use position, the insertion portion of the key forms the short leg of the L-shape. The key holder forms the long leg of the L-shape. In Bosco et al., the short end of the L-shaped lever thereof has a slot that receives the head of a key. In either case, the operator is required to hold the long leg of the lever to twist the key. This is a difficult act for persons with arthritic hands and fingers.
U.S. Pat. No. 4,637,238 to Uda et al. discloses a folding key in which a key body is pivotally mounted in a dished cap. In a storage position, the insertion portion of the key is tucked within the dished cap. To use it, the operator must pivot the insertion portion of the key from the storage position to an in-use position. The operator inserts the insertion portion of the key into the lock and rotates the key by grasping and turning a knob on the cap or the circumference of the cap. The act of pivoting the insertion portion of the key is a difficult act for a person with arthritic hands and fingers. Further, since the key is attached to the cap, multiple keys each with its own dished cap are bulky and take up too much space in a pocket or a handbag.
U.S. Pat. No. 5,058,465 to Womack discloses a device for holding a lock key firmly while inserting the key in a lock for use by a locksmith to make a key by impressioning. The device is too large and bulky for practical use by the public with arthritic hands and/or with multiple keys each having such a device.
Des. 286,465 to Attwood discloses a key holder which attaches to a key. U.S. Pat. No. 6,164,102 to Gapco discloses a bulbous hand grip to facilitate turning a key within a lock. Again, multiple keys would be a problem.
Thus, there continues to exist a need for a device to assist in turning keys, particularly for arthritic persons that are convenient and compact.
An apparatus is provided for facilitating the turning of a key in a keyhole of a lock, which may be called a key wrench. The key has a head, an insertion portion and a connecting portion between the head and the insertion portion. The apparatus has a body for gripping by an operator and applying torque to the key. The body has at least a front surface, a back surface, a peripheral edge where the front and back surfaces meet, and a slot extending through the body between the front and back surfaces. The slot is adapted to allow the insertion portion of the key to extend beyond the front surface and engage the connecting portion when the key is inserted through the slot. In this manner, when torque is applied to the peripheral edge by the operator, the torque is transmitted through the body at least to the connecting portion of the key. This facilitates the turning of the key when the insertion portion is in the keyhole of the lock.
The body may be planar or curved in shape. In a curved shape, the front surface may be concave and the back surface may be convex, or vice versa.
The peripheral edge defines a continuous closed line. The closed line may be, for example, a polygon, a circle or an ellipse. The peripheral edge may be a scalloped edge.
The body may be a paraboloidal body. In one embodiment, the paraboloidal body is a spherical section, wherein the spherical section is at most half of a corresponding sphere. Preferably, the spherical section is less than half of the corresponding sphere.
When the body is a paraboloidal body, one of the front and the back surfaces is preferably a flat surface. In such an embodiment, the slot has a main axis that is preferably substantially perpendicular to the flat surface. Preferably, the length of the slot along its main axis is at most the length from the head to but not including the insertion portion.
In a preferred embodiment, the front surface is convex, the back surface is concave, and the peripheral edge is scalloped. A hole may be provided near the peripheral edge for attachment of a key or a plurality of keys using a chain of sufficient length to allow the insertion portion of the selected key to be inserted through the slot. Less space is taken up in a pocket or handbag this way and the apparatus allows the operator to more easily locate dropped keys.
The apparatus of the present invention provides more comfortable finger surface on the peripheral edge located at an increased radial distance from the main axis of the key. This increased radial distance allows for greater leverage in turning the key. This is particularly beneficial to persons with arthritic hands and fingers.